Drew Weissman is an American immunologist known for his groundbreaking research in the field of mRNA technology. He is a professor at the Perelman School of Medicine at the University of Pennsylvania and has made significant contributions to vaccine development, particularly in the context of COVID-19. Weissman, along with his colleague Katalin Karikó, developed a method to modify mRNA, which has been crucial for the success of mRNA vaccines like the Pfizer-BioNTech and Moderna COVID-19 vaccines. Their work has opened new avenues for treating various diseases, including cancer and genetic disorders.